Double-acting pump.



3. E. REXROTHI DOUBLE ACTING PUMP.

APPLIOATION FILED tsm. 190e.

Patented Nov. 16, i909.

, twinv upper inducingV andeducing chamber UNITED .STATES JOHN J. REXROTH, 0F CHICAGO, ILLHJ'OIS.`

DOUBLE-ACTING PUMP.

Speoication of Letters Patent.

Patented Nov. 16, 1909 Application led February 5, 1909. Serial No. 476,298.

fo atl whom may concern.

Be it known that l', J oHN J Rnxuo'ru, a citizen or' the United `States, 'residing at Chicago, in the county of Cook and'State of Illinois ha ve invented certain new and uselul impr-nements iu Double-Acting` Pumps, of which the :following is a specification.

The objects of the present invention are to obtain, in a pump barrel or cylinder havuns;` a unitorm diameter' from end to end and by tir ot' one pump rod and an upper :un 'er piston, both pistons of the salue dir a lift or raise of water with each up and (flown stroke of the pump rod and pistons under conditions by which the volume of water raised and discharged with each upstrolie, will equal in amount the full capacity of the barrel orcylinder, and the volume of water raised and discharged at each downstroke, will equal in amount, approximately, the full capacity of the barrel or cylinder.

A t'urther object is to furnish a space in the pump barrel or cylinder between a lower piston and a fixed cross-head or wall, in which space the lower piston travels and by its travel creates and maintains a vacuum,` thereby formiV g a cushion to carry a weight oit'purnp rod equal in amount to the air pressure. i y

A further object is to furnish a lower in- -duoin l' and educing chamber for water, lo-A cated ielow a lowerpiston and from which the water can be drawn orsucked into a ier water, located above a cross-head or wall and below an upper piston and valve,-- the water passing from 'the lower inducing and educing` chamber through a hollow iniperforate piston rod or transmission tube into the twin upper inducing and educing chamber and out of the barrel or cylinder of the pump at the point of discharge;

A further object is to connect `an upper and a lower piston, each of the same diameter, by a hollow iinperforate piston rod or transmission tube, and thereby draw or suck water into both a lower and an upper in- ,ducing and educing chamber on the upstrolre or ascent o, the pislons; and on the downstroke or descent of the pistons discharge water from both the lower and upperA inducing and educine chambers, for' the. water to pass above tie upper piston, and

valve' and an equal amount be finally discharged with each up and down stroke of the pistons,

A further object is to furnish a lower induction and eduction chamber into and from which water is induced and educedvby a packed and sealed lower piston and a hollow iniperorate piston rod or transmission tube and an upper twin or companion induction and eduction chamber into and from which vwater is induced and educed by an upper packed and sealed piston and the hollowA iinperforate piston rod or transmission tube, thus inducing into the pum n barrel or cylin der, at the same time an with the same movements of the pistons, two approximately equal volumes of water, which are educ-ed with the up and down stroke oi the pistons, 'one valume on the upstroke and one volume on the downstrolre.

'A further object is to create a perfect suoton and seal' between a lower piston and an upper piston, both of the saine` diameter, and an inclosing pump barrel or cylinder, consisting of an upper section and a lower section, separated by a sealed cross-head or wall, by which water will be drawn or forced into and from an endwise expansible and .contractiblev lower induction and eduction chamber by the lower piston, to be drawn or forced by the upper piston, through a hollow imperforate piston rod or transmission tube, connecting the two pistons, into an endwise expansible and contractible chainber between the upper piston and above the fixed cross-head or wall.

Other objects are to effectively seal and separate the lower chamber and the upper chamber by a lixed cross-head or'wall, and thereby cause the water to pass from the twin lower chamber to the twin upper` chamber, without passing into the space below the `fired cross-head or wall above the lower piston; and to improve generally' the .construction and operation of the pump as a whole. l

The invention consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings Figure Y1 is a sectional elevationy of a pump4 barrel or cylinder broken oli1 "at its upper end and showing,r the construction and arrangement-,of the fixed head or cross-wall, the upper and lower in ductionland eduction chambers, the lupper and lower pistons and their .connecting hol- 1rol ytion and a lower section.

low piston rod or transmission. tube, andarrow. Fig. 3, a cross-section on dotted line vb b of Fig. l, looking in the direction of the arrow; and, Fig. 4, a cross-section on dotted line c c or' Fig. 1, looking in the direction of the arrow.

The pump has a barrel or cylinder l, which, as shown, is formed of an upper sec- At the lower end; of the barrel or cylinder l isa cross-plate or-wall 2, with an annular rim or flange 3 threaded into the end of the barrel or cylinder or otherwise secured in position. rlhe bottom plate or cross-wall 2 has an opening or inlet 4 for admitting water, which opening, as shown, is controlled by a fiap valve 5, pivoted at one side to ears 6 on the bottom or cross-Wall 2, and constituting the induction valve for the lower'section of thebarrel or cylinder; but this induction valve could be of any other suitable form of construction.

Above the induction valve in the pump barrel or cylinder is located and operates the lower piston, the space between the piston and the induction valve formingthe lower induction and eduction chamber. The lower piston consists of an annular ring 7, havin an upwardly extending annular rim or wal 8 with an exterior screw thread, and a top plate 9, having a depending annular rim 10 with an interior screw thread engaging the exterior screw thread of the rim or wall 8 and uniting the ring 7 and top wall 9 to each other. An annular ring 11 is located in the space or recess 'formed between the top wall 9 and lower ring 7, and between the depending wall or Vfiange 10 and the wall of the pump barrel; and on the upper side of this interposed ring 11 is a packing 12, preferably of cup leather and below the interposed ring 11 and around the upper side of the ring 7 is a packing 1 3, also preferably of cup leather-which two packings are coinprcsscd and held in place by and between the interposed ring and the bottom ring and top plate, so as to furnish a close joint and seal around the periphery of the piston, between the piston and barrel or cylinder on the downstroke of the piston, thereby sealing the periphery of the piston, when the pump is primed with water, against the passage of' water and air, as the piston moves down in the barrel or cylinder.

The top plate 9 has a central upwardly projecting rim or neck 9a .with an intcrior` screw threadl into which is threaded the lower end of a hollow imperforate piston rod or transmission tube 14, with a space 15 betweenthe exterior of the hollow imperferate piston rod or transmission tube and the Awall of the pump barrel or cylinder, in which space, below a fixed cross-head or wall, the

lower piston travels. The fixed cross-head or wall 16, as shown, has a central circumferential flange or bead 17, above and below which is an exterior screw thread, and a bottom plate or wall 18 having a central hole 19 tor the passage of the hollow piston rod or transmission (tube. 'lhe fixed crosshead '.or wall 16 has an interior annular chamber 20, the upper part of the wall ot' which has an interior screw thread. The chamber 20 has located in its lower portion a loose or free annular ring 21, and the upper' part of the chamber 2U receives aring Iollower 22, having an exterior screw thread to engage the interior thread of the wall of the chamber in the fixed cross-head or wall 16; and, as shown, the top of the ringfoh lower 22has holes 23 for a turn key or wrench, by 'means of which the ring follower 22 can be entered into position. The loose or free ring 21 has on its under and inner side a packing 24, preferably cup leather, and the ring follower 22 has on its under and inner side a packing 25, preferably cup leather, which packings 2l and 25 are compressed, so as to make a tight joint around the hollow piston rod or transmission tube, by ad aucing the ring follower 22 as required. I

The lower' portion of the cross-head or wall is threaded into the upper end of the lower section of' the pump barrel or cylinder, until the end of the barrel or cylinder and the circui'nferential,flange or bead 17 abut, and the upper section of; the pump barrel or cylinder is threaded on to the upper portion Vot' the fixed cross-head or wall, until its end abuis the flange or bead 17; so that when the sections are united vto the cross-head or wall, the cross-head or wall will be held in a fixed position within the pump barrel or cylinder, with a tight close joint :for the chamber below and the cha-mber above the fixed cross-head or wall, which chambers, when the pump is primed with water, are sealed against the passage or' air and water around the outer circumference of the fixed cross-head or wall, while the cup leather packings- 24 and'25 seal the chambers against the passage of Aair and water around the exterior of the hollow' imperforatrpiston or transmission tube, when the pumpl is fully primed and in operation.

The upperpiston is located above the fixed cross-head or. wall; and between this piston and the fixed cross-head or wall is the upper induction and eduction chamber 'for the water, corresponding to and having the same capacity as the lower induction'and eduction'chamber. The upper piston consists of an annular lower ring 26, fitting the interior of the pump barrel or cylinder and having a bottom late or wall 27, with a depending boss or ub 28 having an interior screw thread into which is entered the upits upstroke.

per end of the hollow piston rofl or transmission tube; and the bottom plate or wall has a series of holes or passages 29, tui-inshmpl has an upwardlyextending,l annular rim or wall 30, with an exterior screw thread and of a less diameter than the diameter of the lowery ring. Anv upper annular ring 3l is located above the bottom or lowel annular ring; and this upper ring `has a depending annular rim or wall 32, with an exterior screw thread engaging the exterior screw i thread of the wall or rim 3() and unit ing the two rings one to the other. lThe upper ring 3l. has inwardly extending arms 33, unitingl the ring to a central boss or hub 3l, so as to leave openings between the ring and the boss or hub for the passage of water from inside of the hollow piston as a whole. A tree or loose annular ring` located in the space between the upper and lower outer rings and the wall of the pump barrel or cylinder; and between this intermediate ring and the under face and outer side of the upper ring; 3l is a packing 3U, preferably'a cup leather packing. )i packing:r 3T, also, preferablV a cup leather packing, is located between the upper tace of the lower annular ring andthe under and outer face oi the intermediate ring. The two packings Btl and 37 are compressed and held in place by advancinzgT the outer upper ringl 3l; and these parkings furnish a. tight joint between the piston, a whole, and the wall of the pump barrel or cylinder, which joint etlectually prevents the escape of water and air around the periphery ot' the piston, on A pump rod 38 is threaded at .its lower end into the central boss or hub 34 of the upper ring' 3l of the upper piston;A and this pump rod at its upper end is to be connected to a handle, or other operating means, in any usual and well known manner. An upper eduction valve is located above the upper piston. is shown this upper educlion valve is atlat faced disk Valve, haring a boss or hub 39 with spokes 40 encircling and free to slide up and down on the pump rod; and having a body or plate -Lll attached to the spokes 40 of a dia'i'neter to cover and close the eduetion openings or passage -li between the Varme ofcth'e upper ring' 3l. when the valve is down, and t0 unclose these openings or passages, when the Valve is raised.

lln pump is assembled` by attaching the lower or induction valve to the lower end of its section of the pump barrel or cylinder; the lower pistou, with its secti ns united to eon'ipress the cup leather packing's, attached to the lower end of the hollow :iinperforate piston rod or transmission tube, and the lower piston and the hollow imperforate .piston rod or' transmission tube are an inlet into the chamber ot' the upper i piston. The outer lower peripheral ring' 26 entered into the lower section of the pump barrel or cylinder, for the cup leather packings to malte an air and water tight joint between the piston and the pump barrel or cylinder, andA when entered the piston will form an endwise expansible and contractible lower induction and eduction chamber for' the water within the barrel or casing, between the lower piston and the lower or induction valve. The fixed cross-head or wall is entered on to theuupper end of the hollow imperforate piston rod or transmission tube, and then ythreaded `or otherwise secured in the upper end ot' the lower section of the pump barrelA or cylinder, so as to tightly close the upper end of said sete .tion of the bai-rel or cylinder. 'The upper pistou, with its sections united to compress the cup leather packings, is attached to the projecting upper end oi' the hollow impert'orate piston rod or transmission tube. i he pump rod is'connected to the upper piston, and the upper or eduetion valve is slipped on to the pump rod to rest on the top face of the upper piston. The upper section of the pump barrel or cylinderisthreaded or otherwise secured to the fixed cross-head or wall, so as to tightly close the lower end of said section of the barrel lor cylinder; and when the upper piston is in place the cup leather packings make an air and water tight joint between t-he piston and the pump barrel or cylinder, and form an endwise eX- pansible and contractibl upper induction .and eduction chamber, between the upper piston and the fixed cross-head or wall, corresponding to and the twin as to capacity of the lower induction and eduction chamber, when the pump is assembled.l

The space above the upper piston, within the pump barrel or cylinder, forms a receiving'a'nd discharging chamber into which the Water is lifted or raised and from which the water is discharged, through a suitable spout orgiiozzle not shown), with each up and down stroke of thepiston; and when the pump is sealed fixed cross-head or Wall and the sealed lower piston, within. the pump barrel or cyl-` inder, has therein a vacuum, created and maintained by the ,sealed lower piston, which vacuum furnishes a cushion for the pump rod.

The operation is as' follows: The initial up and down strokes of the pistons will prime or charge the pump barrel vor cylinder ,with-,water` the priming or chargingy continuing` until the upper receiving chamber is filled-to a point for discharge' ot' 'the next succeeding volume oi water-raisedA and projected thereinto; and# when the pump is ully primed orcliarged,.th'e upper and and educing chambers are lower .inducing their respective pistons against sealed by peripheral primed the space between theescape of aix-j and water armed' the pistons, so that each up and down stroke will discharge a' Volume` of water from the pump of approximately the saine amount.

The lower piston acts on each upstroke and sucks or draws the lower induction and eduction chamber full of water; and at 'the saine time the upper piston acts on each upstroke and sucks or draws the twin upper induction and eduction chamber full of. wa-

ter, the water for the upper induction and pistons two volumes of water of approxitube.

mately the same amount are simultaneously drawn into the pump barrel or cylinderthe amount entering or drawn into the sealed upper chamber being slightly lless than the amount entering-or drawn 'into the sealed lower chamber, owing to the presence of the hollow piston rod or transmission The induction or lower valve is opened with each upstroke of the pistons, so

as to admit water into the twin 4upper and lower induction and eduction chambers; and the eduction or upper valve is closed with each upstroke ol the'piston so that with each `upstrokc .a Volume ofwater will. be raised in and discharged from the receiving chamber above the upper piston by the upstroke of said piston, thus discharging a volume of water at the same time .that two volumes are sucked or drawn into the Apump barrel or cylinder with and by the upstroke of the pistons.4 y

The induction or lower valve is closed and the eduction or upper valve is opened with the downstroke ot' the pistons; and with each downstroke of the pistons, the volume of water sucked or drawn into the upper induction' and eduetion'hamber is forced therefrom into the receiving chamber above the upper piston; and, at thel saine time, the Volume of water sucked or drawn into the lower induction and eduction chamber is forced therefrom, througlrthe hollow imperforate piston rod or transmission tube,` into and through the upper piston to pass into the re. ceiving chamber above the upper piston. lt will thus be seen that, inasmuch as two volumes of water of practically the same amount are forced into the receiving chamber at one and the same time, it follows, owing tothe receiving chamber having discharged but one volume of water on the upstroke, that one volume of the two volumes forced into the receivingvchaniber on the downstrok'e of the piston, must displace -or pass the other and be discharged from the pump," thus making the pump a double acting one with but a single pump vbarrel or cylinder and but one pui'np rod, but discharging water both on the upstroke and on the downstroke. This result or' a 'full dischar ev on both the upstroke and on the downstrole `or" the pistons inasingle pump barrel or cylinder, and with a single pump rod is obtained by the sealed fixed cross-head or wall, and the sealed upper and lower pistons, both of the same diameter and connected by the Ahollow imperfor'ate pis- 75 ton rod or transmission tube, which furnishes a free communication between the twin upper and left-'er induction and eduction chambers, each of the same capacity, and the receiving or final discharge chamber.

The first upstroke of the pistons will eX- haust or educe any air or water in the space between the sealed fixed cross-head or wall and the sealed lower piston-the air and water escaping around the hollow impertorete piston rod or transmission tube, at

` the point of passage through the sealed Xed cross-head or wall, or between the sealed lower piston and pump barrel or cylinder or both, until the pump has been fully primed with water making a water seal, which efectually closes the space between the sealed" cross-head or wall and the sealed lower piston, producing a vacuum in said space, for

the reason that the packing around the pistons will prevent anyair from entering this l space with the succeeding down'stiolre f the pistons, the result being the production of a practically perfect vacuum in the space between the sealed cross-head or wall and the sealed lower piston; and this Vacuum will furnish a cushion to carry a weight of pump rod to an amount equal to the air pressure; and this carrying of the weight of the pump rodis ot great Aassistance in operating the pump. It will be understood that the Vacuum is created and maintained shortly after the beginning ot' the downstroke and until at or near the completion of the upstroke of the piston. A After the pump is once primed or charged, the upstrolie or ascent of .the sealed upper piston creates a suction, betweenthe piston and the sealed fixed cross-head or wall, 'by

which a volume or quantity of water, ap- 115 proxii'nately-equal tothe area of thepump barrel or cylinder multiplied by the length of stroke of the pistons, will be drawn or sucked into the chamber above the fixed cross-head or wall,\through the hollow im- 120 perforate piston rod or transmission tube. At the same time or simultaneously,,the

upstroke or ascent of the lower piston creates a suction` between such sealed piston and the lower or induction valvefby which a volume'l 125 or quantity ofl water, equal to the area of the pump cylinder inultiplied\lby the length of .stroke of the pistons, lwillibe drawn or sucked into the chamber beldwfthe lower piston. Each upstroke of the' piston thus 130 induces into the pump barrelpr cylinder, as a whole, two volumes or quantities of water, each of approximately the capacity' of the area of the barrel or cylinder multiplied by the length of stroke of the pistons, for the 'simultaneous discharge of the two volumes from the respective chambers with each downstroke of the pump rod and pistons. The two volumes will pass into the pump barrel or cylinder above the upper piston,

and one volume will be discharged at the exit of the pump, while the other volume will remain in the pump barrel or cylinder above the upper piston and be discharged with the next succeeding upstroke.

Ity will be seen that a discharge of approximately a full vol'ume of water is obtained at each up and down strokeof the pump rod and pistons. The downstroke of the sealed upper piston will force into the chamberot the pump barrel or cylinder above such upper piston and valve, the full volume ot' water, sucked or drawn into the upper chamber above the vli-xed cross-head or wall by r'neans of the upper piston and the upper eduction valve. At the same time or simultaneously, the downstroke of the sealed lower piston will force upwardly the full volume of water, drawn or sucked by the preceding upstroke of the pistons into the lower chamber above the induction or bottom valve, for such volume of water to pass above the fixed crosshead or wall and through the upper piston and the e'duction or top valve into the receiving and discharg- -ing chamber of the pump barrel or cylinder, above the upper piston and the eduction valve. The two volumes of water thus brought toeether in the receiving and discharging chamber of the pump barrel or cylinder, will eHect a final discharge of one volume by adding the lower volume of water to the upper volume of water, in the chamber above the upper piston, thereby forcing out one volume at the discharge of the pump with each downstroke of the pistons, leaving a volume still in the receiving and discharging chamber to be discharged with each npstroke of the pistons.

The volume of water in the upper induction and eduction chamber, which is trans-- ferred therefrom to pass above the upper piston and valve` constitutes one column of water; and the volume of water, passing through the hollow' piston rod or transmission tube and transferred from the lower induction and eduction chamber to the chamber above the upper piston and valve, alsoconstitutes a column of water, with the result that the lowerinost column acts and forces the uppermost column to be discharged troni the pump with each downstroke of the two pistons, so that in'eiiect two volumes of water or approximately the .same amount areforced at one and the same timejinto a common receiving and discharging chamber, forone volume to be dis charged from the receiving and discharging chamber by passing 'the other volume, as two volumes cannot occupyvthe same space at the same time.

W hat .l claim as new and desire to ny Letters latcnt is:

l. ln a double acting pump, the combina tion ot a cylinder having an impert'oi'ate wall and oi' uniform interior diameter from end to end. a fixed crbssdiead dividing the interiorot the cylinder into a lower .section closed at its upper end and an upper section closed at'its lower end, a piston having a central chamber and operative below the fixed cross-head in the lower section of the cylinder and creating and maintaining a vacuum between the piston and cross-head, the piston having downwardly extending circumferential packing rings, a piston having a central chamber and operative above the fixed cross-head in the upper section of the cylinder, the piston having upwardly extending circumferential packing rings, the fixed cross-head furnishing a lower and an upper induction-eduction chamber, each endwise expansible and contraetible by and with the strokes of the pistons and of the same capacity approximately, and a hollow imperforate piston rod'connecting the central chambers of the two pistons and slidable through the Fixed cross-head, the hollow piston rod or transmission tube and the chambers of the two vpistons furnishing a conduit between the induction -eduction chambers of the sections of the 'cylinder belowl and above the fixed cross-head, substantially as described.

2. In a double acting pump, the combination of a cylinder having an imperforate wall and of uniform interior diameter from end to end, 'a fixed cross-head having a central packing and dividing the interior -of the cylinder into a lower section closed at its upper end and an upper section closed atits lower end, a piston having a central chamber and operative below the fixed crosshead in the lower section ot' the cylinder and creating and maintaining a vacuum between the piston and cross-head, the piston having around its periphery downwardlyextend-A ing cup leather packing rings, a piston having a central chamber and operative above the fixed cross-head in the upper section of the cylinder, the piston having around its periphery upwardly extending cup leathe'i` packing rings, the iixed crosshead furnishing a lower and an upper induction-eduction chamber, each endwise expansible and contractible by and with the stroke of the pistons and ot' the same capacity approximately, and a hollow imperforate.

piston rod connecting the'two pistons and slidable through the fixed head and its packn ing, thehollow piston rod or transmission tube and the chambers of the two pistons furnishing a conduit between the inductioneduction chambers of the sections of the cylinder below and above the cross-head, substantially as described. l

3. In a double acting pump, the combination of a cylinder having an imperforate wall` and of uniform diameter' from. end to end, a ixed cross-head having a central packing and dividing the interior of the cylinder into a lower section closed at itsl upper end and an upper section closed at its lower end, a peripheral packed piston having a central chamber and operative below the fixed head in the lower section of the cylinder and creating and maintaining a vacuum between the piston and cross-head, a peripheral packed piston having a central chamber and operative above the fixed head in the upper section of the cylinder, the fixed cross-head furnishin, r a'lower and an upper induction-eduction chamber, each endwise expansible and contractible by and with the stroke of the pistons and of the same capacity approximately, a hollow imperforatc` piston rod connecting the two pistons and slidable through the iixed head and its packing, the hollow piston rod or transmission tube and the ch-ambers of the two pistons furnishing a conduit between the inductioneduction chambers of the t-wo`sections of the cylinder above and below the fixed crosshead, an induction valve below the lowerv piston, a pump rod connected to the upper piston, an/d an eduction valve 'above the upper piston and carried by the pump rd, substantially as described.

.4'. In a double acting pump, the combination of a cylinder having an imperforate wall and 4of uniform diameter from `end to end and having its interior divided into upper and-lower twin sections, the lower section closed at its upper end and the upper section closed at its lower end, each section having an inductiou-eduction chamber of the/same capacity approximately, a peripheral sealed piston for each section of the cyllfinder, each piston having an upper and lower peripheral packing ring, the ring of the lower piston extending downwardly and the ring of the upper piston extending upwardly, for sealing the lower piston on the' downstroke and the upper piston on the upstroke, each piston having a central chamber and thelow'er piston. operative inthe lower section of the lower cylinder and creating andmaintaining a vacuum between the piston and cross-head, a hollow imperforate piston rod connecting the two pistons and furnishing, in connection 4with the chambers of the two pistons, communication between the induction-eduction chambers of the twin' sections o f the cylinder, for' simultaneously drawing into 'the induction-eduction chamber of each section of the cylinder anapproximately equal volume of water with each upstroke of the pistons andl discharging a single equal volume of water from the chamber of the upper section of thecylinder with each 'up and with each down stroke of the pistons, substantially as described.

5. In a double acting pump, the combina- -tion of a cylinder having an imperforate wall and of uniform diamete'r from end to end, and having its interior divided into joining ends against communication with 'eduction chamber of the same capacity approximately, a peripheral packed and sealed piston for each section, each piston having two peripheral packings, one packing above the other, and each packingformed of cup leather, both cup leathers of the lower piston downwardly extending and both cup leathers of the upper piston upwardly extending, each piston having a central chamber and the lower pistonoperative in the-lower section of the cylinder and creating kandmaintaining'a vacuumbetween the piston and cross-head, a ,hollow imperforate piston rod connecting the two pistons andA furnishing, in connection with the chambers of the two pistons, communication between the induction-eduction chambers of the twin sections .of the cylinder, and valves controlling the induction and eduction of water into and from the sections ofthe cylinder, substantially as described. y

y 6. In a double acting pump, the combina-A tion of a cylinder having a uniform interior diameter from end to end, a fixed cross-head having a central packing and dividing the chamber of the cylinder into lower and upper twin sections, closed against communication at their adjoining ends by the crosshead, each section having an induction-eduction chamber of the same capacity approximately. a piston having a central chamber and operative in the lower section of the cylinder chamber below the cross-head, Vand creating and maintaining a vacuum between the piston and cross-head, the piston consisting of a lower annular ring having an upwardly extending inner iiange, a top plate having a depending flange, an annular ring interposed between the top plate and the lower annular ring outside of the depending flange of the top plate, and a packing above and below the interposed annular ring,each packing having an exterior rim downwardly extending, a piston having a 'central chamin the upper section of the cylinder chamber, the piston consisting of a lower annular ring i wardly extending inner [lange with inwardly extending arms and openings between the i arms, an upper annular ring having a` deber and operative above the iixed cross-head having a perforated bottom plate and an up-V separate ltwin sections closed at their adeach other, each section having an inductioncylinder chamber, the

pending flange, an annular ring interposed between the lower and upper rings, and a packing above and below the interposed annular ring, each packing- 'naving' an exterior rim upwardly extending', and ahollow imperforate piston rod entered intol the .top plate of the lower piston andthe bottom plate of the 'upper piston centrally of both plates and connectingA the two pistons, and slidable through the fixed head and its packing', the hollow piston rod and the chambers of the two pistons furnishing"r a conduit be` tween the induetion-eduction chambers of the twin sections of the cylinder below and above the cross-head, substantially as described.

' T. ln a double acting` pump, the combination of a cylinder having' a uniform interior diameter from end to end, a fixed cross-head having` a central chamber and dividing the chamber of the cylinder into uppe l and lower twin sections, tlle upper section closed at its lower end and the lower section closed at its upper end, each section having an induction--eduction chamber of the same /capacity approximately, a packing in/ the chamber of the fixed cross-head, the packing formed of a loose ring at the bottom of the chamber, a ringe,` follower for the upper part of the chamber. a packing ring on the under and inner side of the loose ring' and a packing ring on the under and inner side of the ringr follower. a piston having a central chamber and operative in the lower section of the cylinder chamber below the crosshead and creating and n'iaintaining a vacuum between/the piston and cross-head, the piston consistinp of a .lower annular ring having an upwardly extendinginneriiange,V a top plate having` a depending` flange, an annular ring interposed between the top plate and t-he lower annular ring outside of the depending' flange of thetep plate, and a packing above and below the interposed annula'r ring, each packingr havinpr an exterior rim downwardly extending, a piston having a central chamber and operative above the fixed cross-head in the upper section of the piston consisting of a lower annular' ring having a perforated bottom plate and an upwardly extending inner flange with inwardly extending arms and openings. between the arms, an upper annular ring' having,r a depending flange.. an annular ring interposed. between the lower and upper rings` and a packing' above and below i l l l l l l I i i l i l l l i I l the inter osed annular rino, each ackiinr h havimgr an exterior rim upwardly extending, and a hollow nnperferate piston rad entered into the top plate of the lower'piston and the bottom plate of the upper piston centrally of both plates and connecting' the'twa pistons, and slidable through the fixed head w and its packing, the hollow piston rod or vtube andthe chambers ofthe two pistors -havino a central ackiuo c Y, s

'having` a central packing and dividing the chamber of the cylinder into upper and lower twinsections, the upper section closed at its lower encl and the lower section closed at its upper end, a hollow piston ivoperative 'in the induction-educt'ion chamber vof the cylinder below the lixed cross-head and creating and maintaininga. vacuum between the piston and cross-head,'the piston having a central cl'nnnber open at the bottom for the induction and eduction. of water, a hollow piston operative abovethe xed head, he piston having' a central chamber open at the tap for the induction and educticn of water, and a hollow iniperforate piston rod connetting;- the two pistons and in communication with tons. and furnishing with the chambers of the two pistons a crnnluit between the induction-eehuftion chambers of the twin Isections of the cylinder above and below the fixed cross-head, substantially as described.

9. lu a double acting pump, the combina i tion of a cylinder having a uniform interior diameter from end to end, a fixed chess-head having' a. central packing and dividing' the chamber of the cylinder into upper and lower twin sections, the upper Section closed at its lower end and the lower section closed at its upper end, each section having an indiietion-eduction chamber of the same capacity appi.'oximately, a hollow piston operative in the induction-eduction chamber of the cyliinler below the fixed' cross-head and creating and maintaininoa vacuum between the piston and cross-head, the piston having a. central chamber open `attirev bottom for the induction and eduction lof water, a hollow piston operative above vthe fixed cross-head, the piston. having a central chamber open at the top for the induction and ednctiou of water, a hollow impor-forato piston rod connecting the two pistons and in columnnication with the central chambers of both pistons, and furnishing with the chainbers of the two pistons a. conduit between the induction-eduction chambers of the twin sections ofthe c vli nder fixed cross-head, an the lower strokes of abme the induction valve below piston. opened and closed b v the the' piston, and an ednction valve upper piston. opened and closed by the strokes of the piston. substiuitially as described.

1,0'. Tn a double acting` pump` the combination ot' a cylinder having;` a nnifarm interior dian'ieter from end to end. a fixed cross-head the central chambers of both pisabove and below the and dividing the l -induction and eduction of water,- a lrollow piston operative above the iixed head, thepiston having a central chamber open at the top for the induction. and eduction ot water, a hollow imperl'orate piston rod connecting the two pistons and n coininimication with the central chambers of both pistons, and vfurnishing with the chambers oi the two pistons alconduit between. the induction-educ tion chambers of the twin sections of the cylinder above and below the lined. cross head, an induction valve helowjthe lower piston', opened and closed by ther/strokes oit the pistou, au Aeduction ve above the upper piston, opened and closed by the strokes of the piston, and pump rod connected with the upper piston and on which the @duction valve is mounted and operates, substantially as described.

ll. ln a double acting pump,

the conil hination of a cylinder consisting olf an upper section and lower sectiom' each section having an imlcr'tcrate.wall and the same interior dian'ietei1 troni end to end, a fixed crossvwhich the adjacent. ends of the cylinder i section and a lower section, each lng an yn'npertorate wall and the same nr head having a. central packing` and on (closing and sealing the its upper endL and closing' and sealing the upper section ft its lower end, each section ot the cylinder bove and below the crosslieafl having ai inductionoduction chamber holle. chair of the tions are thread lower section saine dimensions and capacity, and a piston ha ving a central chamber and operative in thc section ol thei cylinder hele the ixed cross-head, the piston having around its y'i'eripheryl cup lea V'r paci-:ing ings, each packing ring downwardly extending, 'the piston creatingiA and maintaining vacuum in the lower sectiti'i of the cylinder l'ielow the lise-d @rosalie-wad, substantially as described.

l2. In a double act tion of a c vlu'ider ou :ing ot an upper 'tion havterior diameter 'tronil end to aen l :i lined cross-head having anon ral packing and on to whith the adja e. ends ot the ci), inder sectionsarc threaded, closing and. sealiu lower section at .its upper end, and cl and sealing the upper end, each section of the cylinder above and below the crosshoad having an inductionn eductioa chamber both chambers of the same 1 creating omnp, the ofnnhinav .I o ,.tion at its lower dimensions and capac1ty,'and a piston hav# ing a centrallchamber and operative in the section of the cylinder below the fixed crossh'ead. the piston having around its periphery cup leather packing rings, each packing ring downwardly extending, the piston and maintaining aV vacuum in the lowerv section 'of the cylinder below fixed, cross-head, substantially as described.

13. In a. "double acting pump, the combination of a cylinder consisting of an upper section and a lower section, each section having an imperforate wall and the saine diameter from end to end, a fixed cross-head having a central packing and on to which vthe adjacent ends of the cylinder sections are threaded, closing and sealing the lower .section atl its upper end and closing and sealing thc upper section at, its lower end, each ecl'lon of thefcylinderl above and below the cross-head having 'an inductionednction chamber both chambers of the the same dimensions and capacity, and a\peripheral packed piston having a central chainber and operative in the section of the cylin-` der below the fixed head, the piston creating and maintaining a `vacuum in the lower section of the cylinder below lthe lixed crosshead, substantially as described. p

14. ln a double actingpump, the coinbination ot a cylinder consisting of an upper section and lower section, each section having an imperiorate wall and the same diameter from end to end, a fixed cross-head on to which the adjacent ends of the cylinder sections are threaded, closing and seal-. ing the lower section at its upperj'end and closing and sealing the upper section at its lower end, a peripheral sealed piston for each section of the cylindeigon opposite sides of the cross-head, both pistons of the same diameter, and each piston having an upper and lower peripheralpacking ring, both rings of Athe lower piston extending downwardly and both rings of the upper piston extending upwardly, for sealing the lower piston on the down `strokel and the upper piston on the iup stroke, each piston having a central chamber and the lower pis- `ton creating and maintaining a. vacuum between the piston and-the cross-head, and a' hollow iniperforate piston rod connecting the two pistons and furnishing, in connection with the chambers of the two pistons,

,i communication between the two sections of l the cylinder, for simultaneously drawing into each section of the cylinder an approxin mately equal 'volume of water with 'each upstroke o t' the pistons and discharging a single equalvolume of water from the upper section of the cylinder' with each up and with eachdown stroke of the pistons, sub stantially as described.

l5. In a double acting pu'mp, the combination of a cylinder consisting of an upper section and a lower section; each section hav-- ing an iinperforate wall and the same diam` eter from end to end, a Xed cross-head on to which the adjacent ends of the cylinder sections are threaded, closing and sealing the lower section at its'upper end and closing and sealing the upper section at its lower end, a peripheral double packed ,piston for each section of the cylinder on opposite sides of the cross-head, both pistons of the same diameter, and each piston having a central clamberatlie lower piston creating and maintaining a `va`c`unm termed in the lower sec. tion of the cylinder below t-he cross-head, each ,piston having an upper and lower cup packing, both packings of the lower piston downwardly extending und acting on the downstroke'of the piston and both packings ofthe upper piston upwardly extending and acting on the upstroke of the piston, an iinperforate hollow piston rod connecting' the two pistons and furnishing, in connection with the chamber of the-twopistons, communication between the two sections of the cylinder, an induction and eduction chamber for each piston, an induction valve for the lower section of the cylinder,and an eduction valve for the upper section of the cylinder, for simultaneously drawing` .into each section of the cylinder an approximately equal volume of water with each upstroke of the pistons and discharging, from the upper section of the cylinder, a single equal Volume of water with each up and each down stroke of the pistons, substantially as described.

16. In a double acting pump, the combination of a cylinder consisting of an upper section and a lower section, each section having an iinperforate wall and the same interior diameter from end to end, a fixed crosshead having` a central packing and on to which the adjacent, ends of the cylinder sections are threaded, closing and slaling the upper section at its lower end, andclosing and sealing the lower section at its upper end, a hollow piston operative in the section oi the cylinder below the fixed cross-head and creating` and maintaining a vacuum between the piston and the fixed cross-head, the piston having a central chamber open at the bottom for the induction and eduction of water, a hollow piston operative in the section of the cylinder cross-head, the piston having a central chamber open at the top for the induction and eduction of water, a hollow impert'orate piston rod or transmission tube connecting t-he two pistons and in communication with the central chambers ot' both pistons, and furnishingl with the chambers Vof the two pischamber above the fixed.

tons a conduit between. the sections of the cylinder above and below the I'ixed crosshead, an induction valve below the-lower piston, opened and closed by the strokes of the piston,`an eduction Valve above the upper piston, opened and,closed vby the strokes of the piston, and a pump rod connected with the upper piston and on which the eduction Valve is mounted and operates, substantially as described.

JOHN J. REXROTH. litnesses F. R. F ARMER,

A. J. GnovAinn. 

